An extraction-based verification methodology for MEMS

Abstract

Abstract-Micromachining techniques are being increasingly used to develop miniaturized sensor and actuator systems. These system designs tend to be captured as layout, requiring extraction of the equivalent microelectromechanical circuit as a necessary step for design verification. This paper presents an extraction methodology to (re-)construct a circuit schematic representation from the layout, enabling the designer to use microelectromechanical circuit simulators to verify the functional behavior of the layout. This methodology uses a canonical representation of the given layout on which feature-based and graph-based recognition algorithms are applied to generate the equivalent extracted schematic. Extraction can be performed to either the atomic level or the functional level representation of the reconstructed circuit. The choice of level in hierarchy is governed by the trade off between simulation time and simulation accuracy of the extracted circuit. The combination of the MEMS layout extraction and lumped-parameter circuit simulation provides MEMS designers with VLSI-like tools enabling faster design cycles, and improved design productivity.[682]

One MEMS design tool with maximal six design flows

“…11 The layout generated from solid model and input into the usual layout editor Fig. 12 The layout of the Z-axis accelerometer the geometry patterns of typical components such as masses, comb drives and beams from the layout and converts these components into the corresponding components in the system level (Baidya et al 1999;Baidya et al 2002).…”

Extraction and LVS for mixed-domain integrated MEMS layouts

“…We use a fully fractured representation of the layout geometry which we refer to as the canonical representation [6]. This representation uses the minimum number of rectangles to cover layout area between mutually visible parallel edges of the geometry such that each rectangle and polygon after partitioning has at most one neighbor per edge and each edge is either fully covered by a neighbor or not covered at all.…”

“…This is used to create the FSM through which contiguous sets of beams, joints and electrostatic gaps are passed to either recognize or not recognize the set to be a spring or comb drive, as the case may be. The Joints are defined by the number and the relative orientations of the beams attached to it [6]. Beams are first differentiated based on the electrical properties of the embedded electrodes in the beam.…”

“…It uses an integrated MEMS extractor to convert the given integrated layout into a mixed-domain extracted schematic which can then be used to perform a schematic-versus-schematic comparison with the designed schematic to verify connectivity of elements in the design. The extractor presented here uses the extraction framework introduced in [6] and can handle layout design entry. In addition it identifies domain-specific parasitics in the final layout and hence can be used to verify the true behavior of the integrated system.…”

Design, fabrication, and characterization of out-of-plane W-form microsprings for vertical comb electrodes capacitive sensor

“…Among various types of springs currently used in MEMS sensors, fixed-fixed beams, 7 crab-leg flexure, 8 and serpentine springs 9 are the most commonly used suspension springs. The fixed-fixed beam is stable and stiff, but its deflection range is limited.…”